The data rates at which serial links typically operate are very often greater than the inherent bandwidth capabilities of the channel which connects the transmitter device to the receiver device. Signal integrity analysis is therefore required to determine whether the signal being transmitted, as distorted by the channel, is recoverable by the receiver.

This chapter focuses on the types and sources of jitter in detail. Signal integrity analysis techniques are described using both circuit simulation and statistical analysis techniques.

## 8.1 Probability Density Functions

A probability density function (PDF) defines the probability of a sample *x* having a certain value for the universe of possible values of *x*. In the context of jitter, *x* is defined as the timing deviation of a given edge of the signal, and *p*(*x*) is the probability of the signal edge having this amount of deviation. Before discussing the various contributors to jitter, it is useful to review the mathematics behind two common...